Based upon careful study of the dynamics of heroin spread and maintenance in Chicago neighborhoods, the investigators have developes a field research and intervention methodology for early detection and control of localized heroin epidemics. The approach, which has been successfully tested in two Chicago neighborhoods experiencing heroin spread, has four phases: (1) Upon contact with the first case in a new outbreak, an intensive case-finding effort is launched to assess the parameters of the epidemic. (2) An epidemiologic field team attempts to admit to treatment a sample of those involved to explore the most appropriate modalities and location for treatment services. (3) Attractive and convenient treatment services are provided for all addicts in the area, and efforts are made to involve those who do not actively seek treatment. (4) Persistent outreach efforts are directed at those who resist treatment, and there is a rapid outreach response when new cases develop or treated cases relapse. To evaluate these projects, the field team monitors incidence and prevalence of heroin addiction before, during, and following intervention. Despite the promise of these two field trials, we are not ready to recommend widespread application of our approach. In the pilot projects, no control communities were observed to determine the natural course of heroin epidemics in the absence of intervention. Furthermore, these neighborhoods were chosen to optimize the possibility of successful intervention and data collection. In this proposal we wish to replicate our intervention approach in a controlled field trial. This requires that we "pair" communities receiving intervention with control communities which receive no intervention. Incidence and prevalence of heroin addiction would be monitored in both communities over time. We plan to carry out a series of intervention projects to test the exportability of our model to different types of communities. The presence of our field teams in a number of communities experiencing heroin outbreaks will also permit us to examine sociocultural factors related to primary etiology and interpersonal spread of heroin use.